Obama, Putin Smile, Shake Hands and Will Talk Syria Over Dinner

President Obama and Russia's President Vladimir Putin greeted each other with smiles and a handshake at the G20 summit today and planned to take up a subject that is not on the group's agenda -- Syria.

Putin suggested that the crisis and the U.S. threat to attack Syria be debated over dinner this evening.

"Some of the participants asked me to allot some time for the discussion of other issues which weren't part of our agenda but which are extremely important in the global policy. I'm referring to the situation in Syria. Let's do that during our working dinner so that we do not discuss all the issues at once," Putin said.

The Kremlin strongly opposes Obama's plan to intervene militarily in Syria, suggesting it is only a ploy to topple Syrian President Bashar al-Assad. Putin also believes any Western intervention will spark a wider conflict in the region. He has demanded that the United States receive authorization from the United Nations Security Council before taking action, something that Russia would surely block.

"Any other pretext or method which might be used to justify the use of force against an independent sovereign state is inadmissible and can only be interpreted as an aggression," President Putin said in an a joint interview with the Associated Press and a Russian state-owned television channel this week.

Obama, meanwhile, has sought to rally the world around his call to hold Assad accountable for his alleged use of chemical weapons. The United States has presented evidence it says shows Assad's forces used chemical weapons in an Aug. 21 attack on a Damascus suburb that the White House says killed over 1,400 people including hundreds of children.

"I didn't set a red line. The world set a red line. The world set a red line when government's representing 98 percent of the world's populations said the use of chemical weapons are abhorrent," Obama said during a visit to Stockholm, Sweden, on Wednesday.

White House advisers said the president plans to discuss Syria with leaders on the sidelines of the G20 summit.

In a sign that other parties are just as intently focused on Syria at this week's summit, which usually deals with only economic and trade issues, the United Nations' special envoy for Syria, Lakhdar Brahimi, is now expected to attend the G20 as part of Secretary General Ban Ki-Moon's delegation. Brahimi has been invited to attend a meeting of G20 foreign ministers on Friday morning.

Even before the debate over Syria, the meeting between Obama and Putin was already going to be awkward. The two were scheduled to hold a bilateral summit meeting this week, but Obama backed out last month after Russia granted intelligence leaker Edward Snowden asylum. American officials say the Snowden situation was only the straw that broke the camel's back, citing lack of progress on any of the issues the White House hoped to discuss, including missile defense and arms control.

The last time the two presidents met, on the sidelines of June's G8 summit in Northern Ireland, the differences between the two men and the countries they lead were laid bare. At a joint press conference, Obama was uncharacteristically cold and tense. Putin was perhaps even more so than usual.

That gulf has only widened in the past month, most strikingly over Syria.

Russia has been reluctant to throw Assad, its longtime ally, under the bus. Moscow remains Syria's biggest foreign backer, providing the government with much of the arms and cash it needs to sustain the now two and a half year conflict. Russia has urged the United States to wait for the results of a U.N. investigation into the Aug. 21 attack before taking action.

Obama, however, made clear that he holds Russian intransigence accountable for the ongoing violence.

"I think that international action would be much more effective and ultimately we can end deaths much more rapidly if Russia takes a different approach to these problems," he said on Wednesday.

The White House expressed confidence that Congress will ultimately vote to authorize the use of force in Syria, even as the debate rages within both parties.

Putin does not appear content to sit back and watch things happen. Earlier this week he backed a proposal for Russian lawmakers to lobby members of Congress ahead of the vote, urging them to vote no.

The White House is portraying the vote to authorize the use of force as critical to maintaining American leadership in the world.

"The world looks to the United States as a leader on these issues," Rhodes said.

"By necessity we have to be out front in terms of enforcement of international norms and were the United States to not play that role, there would be a significant vacuum in the international community," he added. "We do not want to send a message that the United States is getting out of that business in any way."